Synthesis and crystal structure of thiocyanato or azido bridged one- or two-dimensional polymeric complexes of cadmium(II)

Four new polymeric complexes [Cd(dmen)(SCN)(2)](n) 1, [Cd(deen)(SCN)(2)](n) 2, [Cd(dmen)(N-3)(2)](n) 3 and [Cd(deen)(N-3)(2)](n) 4 (dmen=N,N-dimethylethylenediamine and deen=N,N-diethylethylenediamine) have been synthesized and characterized by single crystal X-ray diffraction. The various arrangements of thiocyanate anions give a 2-D polynuclear chain of pseudo sixteen membered rings for 1 and a 1-D polynuclear chain of eight membered rings for 2. The 2-D polymeric sheets of complexes 3 and 4 involve the formation of two different rings, one a twenty membered zigzag ring and the other a four membered square ring. The co-ordination environment of the cadmium atom in all the complexes is distorted octahedral. In the azido-bridged complexes the cadmium(II) ions are linked both by end-on and end-to-end co-ordination, whereas in the thiocyanato-bridged complexes the cadmium(II) ions are bridged only by end-to-end co-ordination.